Hybrid approach to reconstruct nanoscale grating dimensions using scattering and fluorescence with soft X-rays

Area of Science:

• Materials Science
• Nanotechnology
• Metrology

Background:

• Scatterometry is a key technique for measuring periodic semiconductor nanostructures.
• Current limitations include challenges in achieving sub-nanometer accuracy and resolving ambiguous solutions for complex structures.
• Soft X-ray scatterometry offers higher resolution but still faces ambiguity issues.

Purpose of the Study:

• To improve the accuracy and reduce uncertainty in nanoscale semiconductor metrology.
• To address the challenge of ambiguous solutions in scatterometry for complex nanostructures.
• To leverage soft X-ray fluorescence analysis in a hybrid approach to enhance scatterometry.

Main Methods:

• Utilizing soft X-ray scatterometry for high-resolution measurements.
• Employing materials with low atomic number elements to enhance sensitivity.
• Integrating soft X-ray fluorescence analysis with scatterometry in a hybrid measurement approach.

Main Results:

• The hybrid approach successfully resolved ambiguous solutions obtained from dimensional reconstruction.
• Reduced uncertainty in determining the shape of periodic nanostructures.
• Demonstrated enhanced sensitivity for complex nanostructures composed of different materials.

Conclusions:

• A hybrid soft X-ray scatterometry and fluorescence analysis approach provides unique and accurate solutions for nanoscale semiconductor metrology.
• This method significantly improves the determination of complex nanostructure geometries.
• The technique offers a pathway to overcome limitations in current scatterometry methods.